The major objective of this proposal is the development of ultrasound as a modality for the treatment of cancer in humans with nonionizing radiation. Continuous wave ultrasound in the frequency range of 300 kHz to 2.5 mHz and with intensities up to 5 W/cm squared will be employed using single and multiple transducer systems of our own design and construction. Pulsed ultrasound will also be used for the treatment of human malignant melanoma at intensities up to 100 w/cm squared and duty cycles varying between one and ten percent to test the hypothesis that "non-thermal" interactions resulting from the amorphous semiconductor nature of the melanin may be exploited in the treatment of this disease. Since the interactions of ultrasound inevitably result in temperature evaluation, treatment of human tumors with magnetic induction hyperthermia will also be carried out in the temperature range beween 43 and 53 C. The efficiacy of these two modalities will then be compared in a wide variety of histological types of tumors. In addition to the application of these modalities by themselves, they will als be combined with ionizing radiation and chemotherapeutic drugs in appropriate regimens. In vitro investigators using tissue culture systems as well as animal tumor and human tumor biopsy specimens will also be carried out to elucidate possible mechanisms for the cytotoxic activity of the proposed modalities and provide guidance for the actual tumor therapy regimens. Studies into the development of prognostic tests for hyperthermic therapy are also proposed.